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40b0b3f8 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* |
3 | * lib/parser.c - simple parser for mount, etc. options. | |
1da177e4 LT |
4 | */ |
5 | ||
6 | #include <linux/ctype.h> | |
8bc3bcc9 PG |
7 | #include <linux/types.h> |
8 | #include <linux/export.h> | |
1da177e4 LT |
9 | #include <linux/parser.h> |
10 | #include <linux/slab.h> | |
11 | #include <linux/string.h> | |
12 | ||
13 | /** | |
b9bffa10 | 14 | * match_one - Determines if a string matches a simple pattern |
25985edc | 15 | * @s: the string to examine for presence of the pattern |
1da177e4 LT |
16 | * @p: the string containing the pattern |
17 | * @args: array of %MAX_OPT_ARGS &substring_t elements. Used to return match | |
18 | * locations. | |
19 | * | |
20 | * Description: Determines if the pattern @p is present in string @s. Can only | |
21 | * match extremely simple token=arg style patterns. If the pattern is found, | |
22 | * the location(s) of the arguments will be returned in the @args array. | |
23 | */ | |
ef4533f8 | 24 | static int match_one(char *s, const char *p, substring_t args[]) |
1da177e4 LT |
25 | { |
26 | char *meta; | |
27 | int argc = 0; | |
28 | ||
29 | if (!p) | |
30 | return 1; | |
31 | ||
32 | while(1) { | |
33 | int len = -1; | |
34 | meta = strchr(p, '%'); | |
35 | if (!meta) | |
36 | return strcmp(p, s) == 0; | |
37 | ||
38 | if (strncmp(p, s, meta-p)) | |
39 | return 0; | |
40 | ||
41 | s += meta - p; | |
42 | p = meta + 1; | |
43 | ||
44 | if (isdigit(*p)) | |
ef4533f8 | 45 | len = simple_strtoul(p, (char **) &p, 10); |
1da177e4 LT |
46 | else if (*p == '%') { |
47 | if (*s++ != '%') | |
48 | return 0; | |
49 | p++; | |
50 | continue; | |
51 | } | |
52 | ||
53 | if (argc >= MAX_OPT_ARGS) | |
54 | return 0; | |
55 | ||
56 | args[argc].from = s; | |
57 | switch (*p++) { | |
b5f54b07 AGR |
58 | case 's': { |
59 | size_t str_len = strlen(s); | |
60 | ||
61 | if (str_len == 0) | |
1da177e4 | 62 | return 0; |
b5f54b07 AGR |
63 | if (len == -1 || len > str_len) |
64 | len = str_len; | |
1da177e4 LT |
65 | args[argc].to = s + len; |
66 | break; | |
b5f54b07 | 67 | } |
1da177e4 LT |
68 | case 'd': |
69 | simple_strtol(s, &args[argc].to, 0); | |
70 | goto num; | |
71 | case 'u': | |
72 | simple_strtoul(s, &args[argc].to, 0); | |
73 | goto num; | |
74 | case 'o': | |
75 | simple_strtoul(s, &args[argc].to, 8); | |
76 | goto num; | |
77 | case 'x': | |
78 | simple_strtoul(s, &args[argc].to, 16); | |
79 | num: | |
80 | if (args[argc].to == args[argc].from) | |
81 | return 0; | |
82 | break; | |
83 | default: | |
84 | return 0; | |
85 | } | |
86 | s = args[argc].to; | |
87 | argc++; | |
88 | } | |
89 | } | |
90 | ||
91 | /** | |
b9bffa10 | 92 | * match_token - Find a token (and optional args) in a string |
1da177e4 LT |
93 | * @s: the string to examine for token/argument pairs |
94 | * @table: match_table_t describing the set of allowed option tokens and the | |
95 | * arguments that may be associated with them. Must be terminated with a | |
96 | * &struct match_token whose pattern is set to the NULL pointer. | |
97 | * @args: array of %MAX_OPT_ARGS &substring_t elements. Used to return match | |
98 | * locations. | |
99 | * | |
100 | * Description: Detects which if any of a set of token strings has been passed | |
edd9334c | 101 | * to it. Tokens can include up to %MAX_OPT_ARGS instances of basic c-style |
1da177e4 LT |
102 | * format identifiers which will be taken into account when matching the |
103 | * tokens, and whose locations will be returned in the @args array. | |
104 | */ | |
a447c093 | 105 | int match_token(char *s, const match_table_t table, substring_t args[]) |
1da177e4 | 106 | { |
ef4533f8 | 107 | const struct match_token *p; |
1da177e4 LT |
108 | |
109 | for (p = table; !match_one(s, p->pattern, args) ; p++) | |
110 | ; | |
111 | ||
112 | return p->token; | |
113 | } | |
a3d2cca4 | 114 | EXPORT_SYMBOL(match_token); |
1da177e4 LT |
115 | |
116 | /** | |
b9bffa10 | 117 | * match_number - scan a number in the given base from a substring_t |
1da177e4 LT |
118 | * @s: substring to be scanned |
119 | * @result: resulting integer on success | |
120 | * @base: base to use when converting string | |
121 | * | |
122 | * Description: Given a &substring_t and a base, attempts to parse the substring | |
edd9334c RD |
123 | * as a number in that base. |
124 | * | |
125 | * Return: On success, sets @result to the integer represented by the | |
126 | * string and returns 0. Returns -ENOMEM, -EINVAL, or -ERANGE on failure. | |
1da177e4 LT |
127 | */ |
128 | static int match_number(substring_t *s, int *result, int base) | |
129 | { | |
130 | char *endp; | |
131 | char *buf; | |
132 | int ret; | |
77dd3b0b | 133 | long val; |
1da177e4 | 134 | |
36c8d1e7 | 135 | buf = match_strdup(s); |
1da177e4 LT |
136 | if (!buf) |
137 | return -ENOMEM; | |
77dd3b0b | 138 | |
1da177e4 | 139 | ret = 0; |
77dd3b0b | 140 | val = simple_strtol(buf, &endp, base); |
1da177e4 LT |
141 | if (endp == buf) |
142 | ret = -EINVAL; | |
77dd3b0b AE |
143 | else if (val < (long)INT_MIN || val > (long)INT_MAX) |
144 | ret = -ERANGE; | |
145 | else | |
146 | *result = (int) val; | |
1da177e4 LT |
147 | kfree(buf); |
148 | return ret; | |
149 | } | |
150 | ||
a317178e | 151 | /** |
b9bffa10 | 152 | * match_u64int - scan a number in the given base from a substring_t |
a317178e JS |
153 | * @s: substring to be scanned |
154 | * @result: resulting u64 on success | |
155 | * @base: base to use when converting string | |
156 | * | |
157 | * Description: Given a &substring_t and a base, attempts to parse the substring | |
edd9334c RD |
158 | * as a number in that base. |
159 | * | |
160 | * Return: On success, sets @result to the integer represented by the | |
161 | * string and returns 0. Returns -ENOMEM, -EINVAL, or -ERANGE on failure. | |
a317178e JS |
162 | */ |
163 | static int match_u64int(substring_t *s, u64 *result, int base) | |
164 | { | |
165 | char *buf; | |
166 | int ret; | |
167 | u64 val; | |
a317178e | 168 | |
4ed97b3c | 169 | buf = match_strdup(s); |
a317178e JS |
170 | if (!buf) |
171 | return -ENOMEM; | |
a317178e JS |
172 | |
173 | ret = kstrtoull(buf, base, &val); | |
174 | if (!ret) | |
175 | *result = val; | |
176 | kfree(buf); | |
177 | return ret; | |
178 | } | |
179 | ||
1da177e4 | 180 | /** |
b9bffa10 | 181 | * match_int - scan a decimal representation of an integer from a substring_t |
1da177e4 LT |
182 | * @s: substring_t to be scanned |
183 | * @result: resulting integer on success | |
184 | * | |
edd9334c RD |
185 | * Description: Attempts to parse the &substring_t @s as a decimal integer. |
186 | * | |
187 | * Return: On success, sets @result to the integer represented by the string | |
188 | * and returns 0. Returns -ENOMEM, -EINVAL, or -ERANGE on failure. | |
1da177e4 LT |
189 | */ |
190 | int match_int(substring_t *s, int *result) | |
191 | { | |
192 | return match_number(s, result, 0); | |
193 | } | |
a3d2cca4 | 194 | EXPORT_SYMBOL(match_int); |
1da177e4 | 195 | |
edd9334c | 196 | /** |
01531ac3 BC |
197 | * match_uint - scan a decimal representation of an integer from a substring_t |
198 | * @s: substring_t to be scanned | |
199 | * @result: resulting integer on success | |
200 | * | |
edd9334c RD |
201 | * Description: Attempts to parse the &substring_t @s as a decimal integer. |
202 | * | |
203 | * Return: On success, sets @result to the integer represented by the string | |
204 | * and returns 0. Returns -ENOMEM, -EINVAL, or -ERANGE on failure. | |
01531ac3 BC |
205 | */ |
206 | int match_uint(substring_t *s, unsigned int *result) | |
207 | { | |
208 | int err = -ENOMEM; | |
209 | char *buf = match_strdup(s); | |
210 | ||
211 | if (buf) { | |
212 | err = kstrtouint(buf, 10, result); | |
213 | kfree(buf); | |
214 | } | |
215 | return err; | |
216 | } | |
217 | EXPORT_SYMBOL(match_uint); | |
218 | ||
a317178e | 219 | /** |
b9bffa10 | 220 | * match_u64 - scan a decimal representation of a u64 from |
a317178e JS |
221 | * a substring_t |
222 | * @s: substring_t to be scanned | |
223 | * @result: resulting unsigned long long on success | |
224 | * | |
225 | * Description: Attempts to parse the &substring_t @s as a long decimal | |
edd9334c RD |
226 | * integer. |
227 | * | |
228 | * Return: On success, sets @result to the integer represented by the string | |
229 | * and returns 0. Returns -ENOMEM, -EINVAL, or -ERANGE on failure. | |
a317178e JS |
230 | */ |
231 | int match_u64(substring_t *s, u64 *result) | |
232 | { | |
233 | return match_u64int(s, result, 0); | |
234 | } | |
235 | EXPORT_SYMBOL(match_u64); | |
236 | ||
1da177e4 | 237 | /** |
b9bffa10 | 238 | * match_octal - scan an octal representation of an integer from a substring_t |
1da177e4 LT |
239 | * @s: substring_t to be scanned |
240 | * @result: resulting integer on success | |
241 | * | |
edd9334c RD |
242 | * Description: Attempts to parse the &substring_t @s as an octal integer. |
243 | * | |
244 | * Return: On success, sets @result to the integer represented by the string | |
245 | * and returns 0. Returns -ENOMEM, -EINVAL, or -ERANGE on failure. | |
1da177e4 LT |
246 | */ |
247 | int match_octal(substring_t *s, int *result) | |
248 | { | |
249 | return match_number(s, result, 8); | |
250 | } | |
a3d2cca4 | 251 | EXPORT_SYMBOL(match_octal); |
1da177e4 LT |
252 | |
253 | /** | |
b9bffa10 | 254 | * match_hex - scan a hex representation of an integer from a substring_t |
1da177e4 LT |
255 | * @s: substring_t to be scanned |
256 | * @result: resulting integer on success | |
257 | * | |
258 | * Description: Attempts to parse the &substring_t @s as a hexadecimal integer. | |
edd9334c RD |
259 | * |
260 | * Return: On success, sets @result to the integer represented by the string | |
261 | * and returns 0. Returns -ENOMEM, -EINVAL, or -ERANGE on failure. | |
1da177e4 LT |
262 | */ |
263 | int match_hex(substring_t *s, int *result) | |
264 | { | |
265 | return match_number(s, result, 16); | |
266 | } | |
a3d2cca4 | 267 | EXPORT_SYMBOL(match_hex); |
1da177e4 | 268 | |
aace0509 | 269 | /** |
b9bffa10 | 270 | * match_wildcard - parse if a string matches given wildcard pattern |
aace0509 CD |
271 | * @pattern: wildcard pattern |
272 | * @str: the string to be parsed | |
273 | * | |
274 | * Description: Parse the string @str to check if matches wildcard | |
edd9334c | 275 | * pattern @pattern. The pattern may contain two types of wildcards: |
aace0509 CD |
276 | * '*' - matches zero or more characters |
277 | * '?' - matches one character | |
edd9334c RD |
278 | * |
279 | * Return: If the @str matches the @pattern, return true, else return false. | |
aace0509 CD |
280 | */ |
281 | bool match_wildcard(const char *pattern, const char *str) | |
282 | { | |
283 | const char *s = str; | |
284 | const char *p = pattern; | |
285 | bool star = false; | |
286 | ||
287 | while (*s) { | |
288 | switch (*p) { | |
289 | case '?': | |
290 | s++; | |
291 | p++; | |
292 | break; | |
293 | case '*': | |
294 | star = true; | |
295 | str = s; | |
296 | if (!*++p) | |
297 | return true; | |
298 | pattern = p; | |
299 | break; | |
300 | default: | |
301 | if (*s == *p) { | |
302 | s++; | |
303 | p++; | |
304 | } else { | |
305 | if (!star) | |
306 | return false; | |
307 | str++; | |
308 | s = str; | |
309 | p = pattern; | |
310 | } | |
311 | break; | |
312 | } | |
313 | } | |
314 | ||
315 | if (*p == '*') | |
316 | ++p; | |
317 | return !*p; | |
318 | } | |
a3d2cca4 | 319 | EXPORT_SYMBOL(match_wildcard); |
aace0509 | 320 | |
1da177e4 | 321 | /** |
b9bffa10 | 322 | * match_strlcpy - Copy the characters from a substring_t to a sized buffer |
b32a09db MA |
323 | * @dest: where to copy to |
324 | * @src: &substring_t to copy | |
325 | * @size: size of destination buffer | |
1da177e4 | 326 | * |
b32a09db MA |
327 | * Description: Copy the characters in &substring_t @src to the |
328 | * c-style string @dest. Copy no more than @size - 1 characters, plus | |
edd9334c RD |
329 | * the terminating NUL. |
330 | * | |
331 | * Return: length of @src. | |
1da177e4 | 332 | */ |
b32a09db | 333 | size_t match_strlcpy(char *dest, const substring_t *src, size_t size) |
1da177e4 | 334 | { |
b32a09db MA |
335 | size_t ret = src->to - src->from; |
336 | ||
337 | if (size) { | |
338 | size_t len = ret >= size ? size - 1 : ret; | |
339 | memcpy(dest, src->from, len); | |
340 | dest[len] = '\0'; | |
341 | } | |
342 | return ret; | |
1da177e4 | 343 | } |
a3d2cca4 | 344 | EXPORT_SYMBOL(match_strlcpy); |
1da177e4 LT |
345 | |
346 | /** | |
b9bffa10 | 347 | * match_strdup - allocate a new string with the contents of a substring_t |
1da177e4 LT |
348 | * @s: &substring_t to copy |
349 | * | |
350 | * Description: Allocates and returns a string filled with the contents of | |
351 | * the &substring_t @s. The caller is responsible for freeing the returned | |
352 | * string with kfree(). | |
edd9334c RD |
353 | * |
354 | * Return: the address of the newly allocated NUL-terminated string or | |
355 | * %NULL on error. | |
1da177e4 | 356 | */ |
ef4533f8 | 357 | char *match_strdup(const substring_t *s) |
1da177e4 | 358 | { |
30f7bc99 | 359 | return kmemdup_nul(s->from, s->to - s->from, GFP_KERNEL); |
1da177e4 | 360 | } |
1da177e4 | 361 | EXPORT_SYMBOL(match_strdup); |